By Marissa Perlman

SACRAMENTO (CBS13) — A repairman from Rocklin is behind bars accused of trying to hurt a customer.

Sean Warner, 38, returned to work Thursday and reportedly told a co-worker he tried to kill someone. His co-worker then called police, who quickly found the victim with life-threatening injuries.

READ MORE: Yuba County Water Agency Could Ship Billions Of Gallons Of Water To Bay Area Amid Drought

The sign outside of Warner’s employer, Overhead Door Company of Sacramento, reads, “We are not speaking about the ongoing investigation,” referring to Warner.

“I’m shocked to hear this in so many ways,” said Jeff Armstrong.

READ: Bicyclist Dies After Crash On Way To Hospital

Armstrong has been neighbors with Warner for five years. We told him his neighbor is accused of attacking a customer in Sacramento after they got into a fight.

The Sacramento County Sheriff’s Office initially heard Warner had shot the victim. But said after the victim was taken to the hospital, it was determined he was attacked with an unknown object. Officials are not releasing what weapon was used during their investigation process.

READ MORE: Rio Linda Sandwich Shop Owner Recovering From Stabbing

The victim is an older man and is in serious condition.

“I am sad and shocked to hear it,” said Armstrong.

ALSO: Police Arrest Man For Deadly Shooting In Manteca Friday Morning

Armstrong says the last conversation he had with Warner four days ago was odd in nature. But that was the first time anything seemed off about his longtime neighbor.

“I’ve always had neighborly conversation with him, and he’s a super nice guy. I’ve seen him out running, he also has a table set up outside in his garage where he plays card games with friends and family,” he said.

MORE NEWS: Sacramento Animal Care Services Pushes For More Help For Homeless Pets

Warner is being held in the Sacramento County Jail without bail on attempted murder charges. It’s still not clear what motivated this attack.

Marissa Perlman